Autotitration of therapy using detected electrical activity

Abstract

This disclosure relates to devices, systems, and methods for autotitrating stimulation parameters. In one example, a method includes controlling an implantable medical device to deliver electrical stimulation to a patient according to a plurality of electrical stimulation parameter sets, each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets defining a respective electrical stimulation signal deliverable to the patient, obtaining, by one or more processors and for each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets, a respective signal representative of an electrical response sensed from the patient in response to the electrical stimulation delivered to the patient according to the respective electrical stimulation parameter set, and determining, by the one or more processors and based on the obtained respective signals, a primary electrical stimulation parameter set that defines electrical stimulation therapy deliverable to the patient by the implantable medical device.

What is claimed is: 
     
       1. A medical system comprising:
 an implantable medical device (IMD): and 
 a lead coupled to the IMD, the lead comprising a plurality of electrodes configured to deliver electrical stimulation to a target tissue site proximate a sacral nerve of a patient and sense one or more bioelectrical signals proximate the sacral nerve, 
 wherein the IMD comprises:
 a stimulation generator programmed to deliver, via at least one electrode of the plurality of electrodes, electrical stimulation to a patient to treat incontinence or overactive bladder according to a plurality of electrical stimulation parameter sets, each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets defining a respective electrical stimulation signal deliverable to the patient; and 
 one or more processors configured to:
 deliver, using at least one electrode of the plurality of electrodes, electrical stimulation to the target tissue site based on the plurality of electrical stimulation parameter sets, wherein at least one of the plurality of electrical stimulation parameter sets is sufficient to induce activity of a muscle fiber or nerve; 
 obtain, using at least one electrode of the plurality of electrodes, for each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets, a respective signal representative of an electrical response sensed from the patient in response to the electrical stimulation delivered to the patient according to the respective electrical stimulation parameter set, wherein the signal representative of the electrical response sensed from the patient comprises a bioelectrical signal corresponding to the activity of the muscle fiber or nerve; 
 titrate electrical stimulation to determine, based on the obtained respective signals, a first electrical stimulation parameter set that defines electrical stimulation therapy deliverable to the patient by the stimulation generator; 
 control delivery, by the IMD, of the electrical stimulation therapy to the patient according to the first electrical stimulation parameter set to treat incontinence or overactive bladder; 
 after controlling delivery of the electrical stimulation therapy to the patient according to the first electrical stimulation parameter set, receive, from an external device and in response to patient feedback entered by the patient into the external device, the patient feedback; 
 in response to the patient feedback, automatically titrate electrical stimulation to determine a second electrical stimulation parameter set; and 
 control delivery, by the IMD, of the electrical stimulation therapy to the patient according to the second electrical stimulation parameter set to treat incontinence or overactive bladder. 
 
 
 
     
     
       2. The system of  claim 1 , wherein the stimulation generator is further configured to iteratively deliver electrical stimulation to the patient according to one electrical stimulation parameter set of the plurality of electrical stimulation parameter sets and obtain the respective signal representative of the electrical response sensed from the patient in response to the electrical stimulation delivered to the patient according to the one electrical stimulation parameter set until electrical stimulation from each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets is tested. 
     
     
       3. The system of  claim 1 , wherein the signal representative of the electrical response sensed from the patient comprises an electromyographic (EMG) signal of the patient. 
     
     
       4. The system of  claim 1 , wherein the signal representative of the electrical response sensed from the patient comprises a nerve recording of an active potential of one or more nerves of the patient. 
     
     
       5. The system of  claim 1 , wherein the implantable medical device is configured to deliver electrical stimulation to a first tissue and sense the electrical response from a second tissue different from the first tissue. 
     
     
       6. The system of  claim 1 , wherein, to determine the first electrical stimulation parameter set, the one or more processors are configured to select one electrical stimulation parameter set of the plurality of electrical stimulation parameter sets as the first electrical stimulation parameter set. 
     
     
       7. The system of  claim 1 , wherein each electrical stimulation parameter set defines an electrode combination, a pulse width value, a pulse frequency value, and one of a current amplitude or a voltage amplitude. 
     
     
       8. The system of  claim 7 , wherein the one or more processors are further configured to generate, based on the obtained respective signals, an interpolation curve for each electrode combination from which electrical stimulation was delivered to the patient, and
 wherein, to determine, based on the obtained respective signals, the first electrical stimulation parameter set that defines electrical stimulation therapy deliverable to the patient by the stimulation generator, the one or more processors are further configured to select, based on the interpolation curves for each electrode combination, a primary electrode combination and an amplitude of the first electrical stimulation parameter set. 
 
     
     
       9. The system of  claim 7 , wherein the one or more processors are further configured to generate, based on the obtained respective signals, a response curve for each electrode combination from which electrical stimulation was delivered to the patient, and wherein, to determine, based on the obtained respective signals, the first electrical stimulation parameter set that defines electrical stimulation therapy deliverable to the patient by the stimulation generator, the one or more processors are further configured to select, based on the response curves for each electrode combination, a primary electrode combination and an amplitude of the first electrical stimulation parameter set. 
     
     
       10. The system of  claim 1 , wherein the electrical stimulation therapy comprises sacral neuromodulation. 
     
     
       11. The system of  claim 1 , wherein each electrical stimulation parameter set comprises a signal amplitude, a pulse width, a pulse frequency, a frequency of bursts of pulses, a number of pulses within each burst of pulses, a duty cycle, and an electrode configuration, and wherein each electrical stimulation parameter set is different from each other. 
     
     
       12. The system of  claim 1 , wherein to titrate the electrical stimulation to determine the first electrical stimulation parameter set, the one or more processors are configured to automatically titrate electrical stimulation by iteratively selecting different values for at least one of pulse width, pulse frequency, frequency of busts of pulses, number of pulses within each burst of pulses, or duty cycle. 
     
     
       13. The system of  claim 1 , wherein the patient feedback comprises feedback that electrical stimulation therapy defined by the first electrical stimulation parameter set is no longer effective or that new symptoms have surfaced. 
     
     
       14. The system of  claim 1 , wherein the patient feedback comprises a rating of the electrical stimulation therapy defined by the first electrical stimulation parameter set and wherein the one or more processors are further configured to:
 determine that the rating is below a predetermined threshold. 
 
     
     
       15. A medical system comprising:
 an implantable medical device (IMD); and 
 a lead coupled to the IMD, the lead comprising a plurality of electrodes configured to deliver electrical stimulation to a target tissue site proximate a sacral nerve of a patient and sense one or more bioelectrical signals proximate the sacral nerve, 
 wherein the IMD comprises:
 a stimulation generator programmed to deliver via at least one electrode of the plurality of electrodes, electrical stimulation to a patient to treat incontinence or overactive bladder according to a plurality of electrical stimulation parameter sets, each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets defining a respective electrical stimulation signal deliverable to the patient; and 
 one or more processors configured to:
 deliver, using at least one electrode of the plurality of electrodes, electrical stimulation to the target tissue site based on the plurality of electrical stimulation parameter sets, wherein at least one of the plurality of electrical stimulation parameter sets is sufficient to induce patient movement; 
 obtain, using at least one electrode of the plurality of electrodes, for each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets, a respective signal representative of an electrical response sensed from the patient in response to the electrical stimulation delivered to the patient according to the respective electrical stimulation parameter set, and a respective movement signal representative of a motion of a portion of the patient in response to the electrical stimulation delivered to the patient according to the respective electrical stimulation parameter set; 
 determine, based on the obtained respective signals, a first electrical stimulation parameter set that defines electrical stimulation therapy deliverable to the patient by the stimulation generator; 
 control delivery, by the IMD, of the electrical stimulation therapy to the patient according to the first electrical stimulation parameter set to treat incontinence or overactive bladder 
 after controlling delivery of the electrical stimulation therapy to the patient according to the first electrical stimulation parameter set, receive, from an external device and in response to patient feedback entered by the patient into the external device, the patient feedback; 
 in response to the patient feedback, automatically titrate electrical stimulation to determine a second electrical stimulation parameter set; and 
 control delivery, by the IMD, of the electrical stimulation therapy to the patient according to the second electrical stimulation parameter set to treat incontinence or overactive bladder, and 
 wherein, to determine the first electrical stimulation parameter set and the second electrical stimulation parameter set, the one or more processors are configured to titrate electrical stimulation to determine, based on the obtained respective signals and the respective movement signals, the first electrical stimulation parameter set and the second electrical stimulation parameter set, that defines electrical stimulation therapy deliverable to the patient by the IMD. 
 
 
 
     
     
       16. The system of  claim 15 , wherein to titrate the electrical stimulation to determine the first electrical stimulation parameter set, the one or more processors are configured to automatically titrate electrical stimulation by iteratively selecting different values for at least one of pulse width, pulse frequency, frequency of busts of pulses, number of pulses within each burst of pulses, or duty cycle. 
     
     
       17. The system of  claim 15 , wherein the patient feedback comprises feedback that electrical stimulation therapy defined by the first electrical stimulation parameter set is no longer effective or that new symptoms have surfaced. 
     
     
       18. The system of  claim 15 , wherein the patient feedback comprises a rating of the electrical stimulation therapy defined by the first electrical stimulation parameter set and wherein the one or more processors are further configured to:
 determine that the rating is below a predetermined threshold. 
 
     
     
       19. A medical system comprising:
 means for controlling a stimulation generator of an implantable medical device to deliver electrical stimulation to a patient to treat incontinence or overactive bladder according to a plurality of electrical stimulation parameter sets, each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets defining a respective electrical stimulation signal deliverable to the patient; 
 means for obtaining, for each electrical stimulation parameter set of the plurality of electrical stimulation parameter sets, a respective signal representative of an electrical response sensed from the patient in response to the electrical stimulation delivered to the patient according to the respective electrical stimulation parameter set, wherein the signal representative of the electrical response sensed from the patient comprises a bioelectrical signal obtained proximate to a sacral nerve of a patient corresponding to the activity of the muscle fiber or nerve; 
 means for titrating electrical stimulation to determine, based on the obtained respective signals, a first electrical stimulation parameter set that defines electrical stimulation therapy deliverable to the patient by the stimulation generator, the first electrical stimulation parameter set being sufficient to induce activity of a muscle fiber or nerve proximate the sacral nerve; 
 means for controlling the stimulation generator to deliver the electrical stimulation therapy to the patient according to the first electrical stimulation parameter set to treat incontinence or overactive bladder; 
 means for receiving, from an external device, after delivery of the electrical stimulation therapy to the patient according to the first electrical stimulation parameter set, and in response to patient feedback entered by the patient into the external device, the patient feedback; 
 in response to the patient feedback, means for automatically titrating electrical stimulation to determine a second electrical stimulation parameter set; and 
 means for controlling the stimulation generator to deliver the electrical stimulation therapy to the patient according to the second electrical stimulation parameter set to treat incontinence or overactive bladder. 
 
     
     
       20. The system of  claim 19 , wherein the means for titrating electrical stimulation comprises means for automatically titrating electrical stimulation by iteratively selecting different values for at least one of pulse width, pulse frequency, frequency of busts of pulses, number of pulses within each burst of pulses, or duty cycle.